Figure 2.

Predicted change in northeast Atlantic benthic marine flora if CO₂ emissions continue unabated. (A) Arctic region: warming will be detrimental to cold-adapted species, and acidification will corrode maerl (M.). Pacific species, for example, Alaria marginata (Am), will invade as polar ice melts, competing with native species such as Laminaria hyperborea (Lh) and Alaria esculenta (Ae). Fleshy invasives, for example, Sargassum muticum (Sm), will move north competing with fucoids, for example, Fucus distichus (Fd), in the intertidal. Acidification will corrode epiphytic calcified algae, for example, Titanoderma pustulatum (Tp), and increased CO₂ levels will stimulate growth of diatoms (D.) (magnified circles) and seagrasses such as Zostera marina (Zm). (B) Boreal region: Laminaria hyperborea (Lh) forests will be increasingly dominated by Laminaria ochroleuca (Lo), with the loss of Alaria esculenta (Ae) and fucoids, for example, Fucus vesiculosus (Fv) and the continued spread of invasive Undaria pinnatifida (Up), Sargassum muticum (Sm), and Grateloupia turuturu (Gt). As in the Arctic, maerl beds will be corroded, seagrasses will thrive, but epiphytic calcified algae will be reduced or replaced with diatoms and filamentous seaweeds (magnified circles). (C) Lusitanian region: kelps will be replaced by smaller, fleshy algae and invasive species, for example, Caulerpa taxifolia (Ct) will proliferate. Fucoids will be replaced by invasives such as Asparagopsis armata (Aa). Seagrasses will thrive, and it is expected that maerl and epiphytic calcified algae will be retained (magnified circles).